scholarly journals BMSCs Regulate Astrocytes through TSG-6 to Protect the Blood-Brain Barrier after Subarachnoid Hemorrhage

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Yilv Wan ◽  
Min Song ◽  
Xun Xie ◽  
Zhen Chen ◽  
Ziyun Gao ◽  
...  

Background. In patients with subarachnoid hemorrhage (SAH), the damage of the blood-brain barrier (BBB) can be life-threatening. Mesenchymal stem cells are widely used in clinical research due to their pleiotropic properties. This study is aimed at exploring the effect of BMSCs regulating astrocytes on the BBB after SAH. Methods. The SAH model was established by perforating the blood vessels. BMSCs were transfected with TSG-6 inhibitor plasmid and cocultured with astrocytes. Intravenous transplantation of BMSCs was utilized to treat SAH rats. We performed ELISA, neurological scoring, Evans blue staining, NO measurement, immunofluorescence, BBB permeability, Western blot, HE staining, Nissl staining, and immunohistochemistry to evaluate the effect of BMSCs on astrocytes and BBB. Results. SAH rats showed BBB injury, increased BBB permeability, and brain histological damage. BMSCs will secrete TSG-6 after being activated by TNF-α. Under the influence of TSG-6, the NF-κB and MAPK signaling pathways of astrocytes were inhibited. The expression of iNOS was reduced, while occludin, claudin 3, and ZO-1 expression was increased. The production of harmful substances NO and ONOO- decreased. The level of inflammatory factors decreased. The apoptosis of astrocytes was weakened. TSG-6 secreted by BMSCs can relieve inflammation caused by SAH injury. The increase in BBB permeability of SAH rats was further reduced and the risk of rebleeding was reduced. Conclusion. BMSCs can regulate the activation of astrocytes through secreting TSG-6 in vivo and in vitro to protect BBB.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Qianshuo Liu ◽  
Xiaobai Liu ◽  
Defeng Zhao ◽  
Xuelei Ruan ◽  
Rui Su ◽  
...  

AbstractThe blood–brain barrier (BBB) has a vital role in maintaining the homeostasis of the central nervous system (CNS). Changes in the structure and function of BBB can accelerate Alzheimer’s disease (AD) development. β-Amyloid (Aβ) deposition is the major pathological event of AD. We elucidated the function and possible molecular mechanisms of the effect of pseudogene ACTBP2 on the permeability of BBB in Aβ1–42 microenvironment. BBB model treated with Aβ1–42 for 48 h were used to simulate Aβ-mediated BBB dysfunction in AD. We proved that pseudogene ACTBP2, RNA-binding protein KHDRBS2, and transcription factor HEY2 are highly expressed in ECs that were obtained in a BBB model in vitro in Aβ1–42 microenvironment. In Aβ1–42-incubated ECs, ACTBP2 recruits methyltransferases KMT2D and WDR5, binds to KHDRBS2 promoter, and promotes KHDRBS2 transcription. The interaction of KHDRBS2 with the 3′UTR of HEY2 mRNA increases the stability of HEY2 and promotes its expression. HEY2 increases BBB permeability in Aβ1–42 microenvironment by transcriptionally inhibiting the expression of ZO-1, occludin, and claudin-5. We confirmed that knocking down of Khdrbs2 or Hey2 increased the expression levels of ZO-1, occludin, and claudin-5 in APP/PS1 mice brain microvessels. ACTBP2/KHDRBS2/HEY2 axis has a crucial role in the regulation of BBB permeability in Aβ1–42 microenvironment, which may provide a novel target for the therapy of AD.


2017 ◽  
Vol 38 (11) ◽  
pp. 1979-1992 ◽  
Author(s):  
Jiajia Zhu ◽  
Xing Li ◽  
Jia Yin ◽  
Yafang Hu ◽  
Yong Gu ◽  
...  

The role of glycocalyx in blood–brain barrier (BBB) integrity and brain damage is poorly understood. Our study aimed to investigate the impacts of endothelial glycocalyx on BBB function in a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Male Sprague-Dawley rats subjected to 8-min asphyxia CA/CPR. Compared to controls, glycocalyx was mildly injured by CA, severely disrupted by hyaluronidase (HAase) with CA, and mitigated by hydrocortisone (HC) with CA. More importantly, the disruption of glycocalyx caused by HAase treatment was associated with higher BBB permeability and aggravated brain edema at 24 h after return of spontaneous circulation, as well as lower survival rate and poorer neurologic outcome at seventh day. Reversely, less degradation of glycocalyx by HC treatment was accompanied by higher seven-day survival rate and better neurologic outcome. Mechanistically, HAase treatment further increased CA/CPR-induced activation of glia cells and expression of inflammatory factors, whereas HC decreased them in the brain cortex and hippocampus. Glycocalyx degradation results in BBB leakage, brain edema, and deteriorates neurologic outcome after asphyxia CA/CPR in rats. Preservation of glycocalyx by HC could improve neurologic outcome and reduce BBB permeability, apparently through reduced gene transcription-protein synthesis and inflammation.


2020 ◽  
Vol 11 ◽  
Author(s):  
Jing Sun ◽  
Jusheng Wu ◽  
Fuzhou Hua ◽  
Yong Chen ◽  
Fenfang Zhan ◽  
...  

Sleep deprivation occurs frequently in older adults, which can result in delirium and cognitive impairment. CD44 is a key molecular in blood-brain barrier (BBB) regulation. However, whether CD44 participates in the role of sleep deprivation in cognitive impairment remains unclear. In this study, the effect of sleep deprivation on cognitive ability, tissue inflammation, BBB permeability, and astrocyte activity were evaluated in vivo. The differentially expressed genes (DEGs) were identified by RNA sequencing. A CD44 overexpression in the BBB model was performed in vitro to assess the effect and mechanisms of CD44. Sleep deprivation impaired the learning and memory ability and increased the levels of inflammatory cytokines, along with increased BBB permeability and activated astrocytes in hippocampus tissue. RNA sequencing of the hippocampus tissue revealed that 329 genes were upregulated in sleep deprivation-induced mice compared to control mice, and 147 genes were downregulated. GO and pathways showed that DEGs were mainly involved in BBB permeability and astrocyte activation, including nervous system development, neuron development, and brain development, and neuroactive ligand-receptor interaction. Moreover, the PCR analysis revealed that CD44 was dramatically increased in mice with sleep deprivation induction. The overexpression of CD44 in astrocytes promoted BBB permeability in vitro and induced the expression of the downstream gene NANOG. Our results indicate that sleep deprivation upregulated CD44 expression in hippocampus tissue, and increased BBB permeability, resulting in cognitive impairment.


2020 ◽  
Author(s):  
Shuaishuai Gong ◽  
Jieman Wang ◽  
Zhuo Chen ◽  
Xuewei Pan ◽  
Yunhao Wu ◽  
...  

Abstract Background : Cerebral ischemia-reperfusion (I/R) injury as a serious threat to human health is characterized by cerebral endothelial leakage, as a result of the damage of blood-brain barrier (BBB). It is thus quite attractive to realize real-time monitoring of BBB damage for therapeutic surveillance.Methods : In this study, a radioactive probe is constructed by conjugating ruscogenin (Rus), a neuroprotectants, to technetium-99m (Tc 99m ) to assess the damage of cerebral endothelial in BBB.Results : In vitro study proves that the probe can penetrate more efficiently in damaged BBB. Then, longitudinal nuclear imaging distinguishes mice with BBB leakage from normal ones, which is validated by evans blue staining of brain tissue. Higher nuclear signal also correlates with poorer blood circulation in brain. Further, by visualizing brain signal during drug treatment, the probe finds that the most obvious protective efficacy of Rus occurs at 12 h post administration, which is superior than edaravone (Edara).Conclusion : Altogether, the probe is promising to monitor I/R injury real-time by radioactive-imaging of BBB integrity. Importantly, Rus as a neuroprotectants may serve as a potential theranostic agent for I/R treatment.


2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  

Abstract The blood-brain barrier (BBB) plays a pivotal role in maintenance and regulation of the neural microenvironment. The occurrence of BBB disruption is the pathological change of early Alzheimer’s disease (AD). RNA-binding proteins and long non-coding RNAs are involved in the regulation of BBB permeability. Our study was performed to demonstrate TRA2A/LINC00662/ELK4 axis in regulating BBB permeability in AD microenvironment. In Aβ1-42-incubated microvascular endothelial cells (ECs) of BBB model in vitro, TRA2A and LINC00662 were enriched. TRA2A increased the stability of LINC00662 by binding with it. The knockdown of either TRA2A or LINC00662 decreased the BBB permeability via upregulating the expressions of tight junction-related proteins. ELK4 was lower expressed in BBB model in vitro in AD microenvironment. LINC00662 mediated the degradation of ELK4 mRNA by SMD pathway. The downregulated ELK4 increased the permeability of BTB by increasing the tight junction-related proteins expressions. TRA2A/LINC00662/ELK4 axis plays a crucial role in the regulation of BBB permeability in AD microenvironment, which may provide a novel target for the therapy of AD.


Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 843
Author(s):  
Bo Kyung Lee ◽  
Soo-Wang Hyun ◽  
Yi-Sook Jung

Yuzu and its main component, hesperidin (HSP), have several health benefits owing to their anti-inflammatory and antioxidant properties. We examined the effects of yuzu and HSP on blood–brain barrier (BBB) dysfunction during ischemia/hypoxia in an in vivo animal model and an in vitro BBB endothelial cell model, and also investigated the underlying mechanisms. In an in vitro BBB endothelial cell model, BBB permeability was determined by measurement of Evans blue extravasation in vivo and in vitro. The expression of tight junction proteins, such as claudin-5 and zonula occludens-1 (ZO-1), was detected by immunochemistry and western blotting, and the reactive oxygen species (ROS) level was measured by 2′7′-dichlorofluorescein diacetate intensity. Yuzu and HSP significantly ameliorated the increase in BBB permeability and the disruption of claudin-5 and ZO-1 in both in vivo and in vitro models. In bEnd.3 cells, yuzu and HSP were shown to inhibit the disruption of claudin-5 and ZO-1 during hypoxia, and the protective effects of yuzu and HSP on claudin-5 degradation seemed to be mediated by Forkhead box O 3a (FoxO3a) and matrix metalloproteinase (MMP)-3/9. In addition, well-known antioxidants, trolox and N-acetyl cysteine, significantly attenuated the BBB permeability increase, disruption of claudin-5 and ZO-1, and FoxO3a activation during hypoxia, suggesting that ROS are important mediators of BBB dysfunction during hypoxia. Collectively, these results indicate that yuzu and HSP protect the BBB against dysfunction via maintaining integrity of claudin-5 and ZO-1, and these effects of yuzu and HSP appear to be a facet of their antioxidant properties. Our findings may contribute to therapeutic strategies for BBB-associated neurodegenerative diseases.


Author(s):  
Ying Wang ◽  
Xinjie Liu ◽  
Qi Liu

Streptococcus pneumoniae meningitis is one of the most common disorders seen in clinical practice. It is believed that the brain tissue immune injury is caused by the expression of pattern-recognition receptors (PRR) which can further induce the release of other cytokines and inflammatory cascades. The aim of this study is to investigate the expression of nucleotide-binding oligomerization domain 2 (NOD2) and inflammatory factors in rat brain tissues infected with Streptococcus pneumoniae and its influence on the blood-brain barrier (BBB) permeability. Rats were given an intracranial injection of Streptococcus pneumoniae to construct the Streptococcus pneumoniae meningitis rat models. The expression change curves of NOD2 and inflammatory factors at different time points (0 h, 12 h, 24 h, 48 h, and 7 d) after Streptococcus pneumoniae were evaluated by enzyme-linked immunosorbent assay (ELISA). Western blotting analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were engaged to examine the expression of NOD2. Furthermore, the changing processes of pathological characteristics, nervous system score, cerebral oedema, and BBB permeability were observed. Our results showed that NOD2 expression began to increase in the 12 h after Streptococcus pneumoniae infection group, while the remaining inflammatory factors were not obviously increased. Meanwhile, the levels of NOD2, as well as inflammatory factors IL-1β, TNF-α, and IL-6 were markedly elevated in 24 h and 48 h infection groups, which were consistent with the increases in BBB permeability and BWC, and the positive expression of NOD2 in the infected rat brain tissues was observed using immunohistochemistry (IHC). This study suggests that NOD2 might be related to the activation of inflammation pathways and the damage to the blood-brain barrier. NOD2 and inflammatory factors have played vital roles in the pathogenesis of Streptococcus pneumoniae meningitis.


2022 ◽  
Author(s):  
Andrew V Stachulski ◽  
Tobias B-A Knausenberger ◽  
Sita N Shah ◽  
Lesley Hoyles ◽  
Simon McArthur

Purpose: The sequential activity of gut microbial and host processes can exert a powerful modulatory influence on dietary components, as exemplified by the metabolism of the amino acids tyrosine and phenylalanine to p-cresol by gut microbes, and then to p-cresol glucuronide (pCG) by host enzymes. Although such glucuronide conjugates are classically thought to be biologically inert, there is accumulating evidence that this may not always be the case. We investigated the activity of pCG, studying its interactions with the cerebral vasculature and the brain in vitro and in vivo. Methods: Male C57Bl/6J mice were used to assess blood-brain barrier (BBB) permeability and whole brain transcriptomic changes in response to pCG treatment. Effects were then further explored using the human cerebromicrovascular endothelial cell line hCMEC/D3, assessing paracellular permeability, transendothelial electrical resistance and barrier protein expression. Results: Mice exposed to pCG showed reduced BBB permeability and significant changes in whole brain transcriptome expression. Surprisingly, treatment of hCMEC/D3 cells with pCG had no notable effects until co-administered with bacterial lipopolysaccharide, at which point it was able to prevent the permeabilising effects of endotoxin. Further analysis suggested that pCG acts as an antagonist at the principal lipopolysaccharide receptor TLR4. Conclusion: The amino acid phase II metabolic product pCG is biologically active at the BBB, highlighting the complexity of gut microbe to host communication and the gut-brain axis.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi85-vi85
Author(s):  
Matthew Smith-Cohn ◽  
Nicholas Burley ◽  
Stuart Grossman

Abstract BACKGROUND Drug delivery to treat neurologic disease and cancers of the central nervous system (CNS) is severely limited by the blood-brain barrier (BBB). Vasoactive peptides (VAPs) such as regadenoson, adenosine, and labradimil have been shown in animal studies to transiently open the BBB, and regadenoson is currently under investigation in humans to determine if it might improve CNS drug delivery. There is currently limited information regarding the potential for other VAPs to open the BBB transiently. METHODS We performed a review of the literature evaluating the physiologic effects of vasoactive peptides on the vasculature of the brain and systemic organs. To assess the likelihood that a vasoactive peptide might transiently disrupt the BBB, we devised a four-tier classification system to organize data available in the literature which factors in alterations in BBB integrity and effects on normal brain vasculature and systemic blood vessels. This data was further sorted based on whether it comes from humans, animals, or in vitro systems. RESULTS We identified 38 VAPs with potential BBB permeability-altering properties. To date, none of these has been shown to open the BBB in humans. Thirteen VAPs increased BBB permeability in rodents. The remaining 25 had favorable physiologic effects on blood vessels but lack specific information on permeability changes to the BBB. We ranked VAPs in a four-tier ranking system related to their known physiologic actions. CONCLUSION Rodent studies document that analogs of bradykinin and adenosine transiently disrupt the BBB leading to higher chemotherapy concentrations in the CNS. VAPs remain an understudied class of drugs with the potential to increase drug delivery to the CNS. Dozens of VAPs have yet to be formally evaluated for this important clinical effect. This retrospective review summarizes the available data on VAPs highlighting agents that deserve further in vitro and in vivo investigations.


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